As the high-technology industry blooms and the telecommunication network advances rapidly, various different computer peripheral devices (such as flash disks, Bluetooth transceivers and portable hardware keys) for microcomputer devices (such as personal computers, digital cameras, personal digital assistants) are introduced to the market, and the price becomes increasingly lower, and thus computer peripheral devices are used extensively. Among these computer peripheral devices, the one with a universal serial bus (USB) transmission interface is very popular in the market and used extensively by users. Since USB computer peripheral devices come with a hot plug function and the capacity of a flash memory is increased continuously, such computer peripheral devices can be provided for designers to code a large number of programs or storing a large quantity of digital data. Therefore, the USB computer peripheral devices become one of the necessary peripherals.
For instance, a flash disk is used for illustrating a computer peripheral device. With reference to FIG. 1, a conventional flash disk 1 comprises a casing 10, a main body 11, a foolproof frame 12 and an external cover 13. The casing 10 is formed by engaging an upper casing 101 and a lower casing 102, and both upper and lower casings 101, 102 have a U-shaped cross-section to define a containing space in the casing 10. The main body 11 is formed by combining a circuit board 111 and a connecting plate 112, and the circuit board 111 is disposed in the containing space and covered within the casing 10 for protecting electronic components on the circuit board 111 from being damaged. The connecting plate 112 is exposed from an end of the casing 10 and has a connecting terminal 1121 disposed on a lateral surface for connecting the connecting terminal 1121 with a circuit on the circuit board 111, such that when the flash disk 1 is plugged into a socket of another microcomputer device, the flash disk 1 is electrically connected to the microcomputer device. The foolproof frame 12 is a rectangular hollow frame, with an end connected to an end of the casing 10 for installing the connecting plate 112 in the foolproof frame 12, so as to prevent users from plugging the flash disk 1 in a wrong direction, and the connecting terminal 1121 of the connecting plate 112 will not be in contact with the foolproof frame 12 to prevent the connecting terminal 1121 from unable to electrically connect to the microcomputer device. A groove 130 is disposed at an end of the external cover 13 and connected to an end of the casing 10 for accommodating the foolproof frame 12 together with the connecting plate 112, so as to prevent the connecting plate 112 from adhering dusts or other foreign matters (such as oil stains, and hairs) or causing a poor contact of a connecting terminal 1121 on the connecting plate 112 with other microcomputer devices when the flash disk 1 is not in use, and thus such arrangement causes an inconvenience of use. When a user wants to use the aforementioned flash disk 1, the user has to remove the external cover 13 from the casing 10 before connecting the connecting plate 112 with a socket of another microcomputer device. When the user uses the flash disk 1, it is necessary to find a place to put the external cover 13, and users may lose the external cover 13 easily without paying attention to where it was put. If the external cover 13 is missing, then the user has to find an external cover 13 of the same model to fit the casing 10, and it definitely causes inconvenience to the use. In addition, the manufacturing process of the aforementioned flash disk 1 is very complicated, and requires installing components one by one. Since the components are made of different materials, the assembling process will be very complicated and the manufacturing cost will be very high.
Therefore, manufactures have developed a rotating foldable computer peripheral device as shown in FIG. 2, the foldable computer peripheral device comprises a casing 20, a circuit board 21 and a bending plate 22, wherein an opening 201 is disposed at an end of the casing 20 to define a containing space 202 therein for fixing the circuit board 21, and a connecting terminal 211 is disposed on a lateral surface of the circuit board 21 and at a position proximate to the opening 201 of the casing 20, and the connecting terminal 211 is not in contact with the casing 20. The bending plate 22 is substantially U-shaped, with both ends parallelly extended outward to a free end, and another end of the opening 201 disposed at a position away from the casing 20 is pivotally coupled to both free ends at a position proximate to the bending plate 22 for turning the casing 20 and accommodating the casing 20 into the bending plate 22, or being turned out from the bending plate 22, so as to overcome the aforementioned issue of having a risk of losing the external cover easily. However, the casing 20 of such foldable computer peripheral device is not fixed into the bending plate 22, the casing 20 may be turned out from the bending plate 22 unintentionally after the user folds and stores the flash disk in a bag, and the casing 20 will be compressed and deformed. As a result, the flash disk no longer cannot be stored into the bending plate 22 anymore. Although the casing 20 can be contained in the bending plate 22, yet both sides of the bending plate 22 are open. Therefore, dusts or foreign matters may enter into the casing 20 easily, and the failure rate of the connecting terminal 211 on the circuit board 21 inside the casing 20 is increased significantly.
In the aforementioned two types of computer peripheral devices, their size is limited by the size of the circuit board and cannot be reduced effectively. Such devices not only fail to meet the compact design requirement, but also consume more materials for the manufacture and incur a higher cost. Some manufacturers use a Chip On Board (COB) technology to integrate all circuits into a circuit board of the computer peripheral device, and build a connecting terminal to be plugged into a socket of another microcomputer device. However, such computer peripheral device does not have an additional component for protecting the connecting terminal, and the connecting terminal may be damaged easily.
Therefore, it is an important subject for computer peripherals manufacturers to design a computer peripheral device capable of preventing the connecting terminal of the computer peripheral device from being damaged and preventing the external cover of the computer peripheral device from being lost easily, so as to avoid inconvenience to users, lower the production cost effectively, and overcome the foregoing shortcomings of the traditional computer peripheral devices.